Control of edge-localized mode in magnetically confined fusion plasmas

A great challenge for fusion energy research and technology is to confine burning plasma while maintaining tolerable steady state and transient heat and particle fluxes on plasma-facing components. When tokamak plasmas operate in a high-confinement (H-mode) regime, a significant increase in the plasma energy confinement time is observed. However, as a consequence, a steep plasma pressure gradient and an associated increased current density at the plasma edge could exceed a threshold value to drive magnetohydrodynamic instabilities referred to as edge-localized modes (ELMs). ELMs lead to quasiperiodic expulsions of large amounts of energy and particles from the confined region, which in turn could result in serious damage to plasma-facing components. The next generation fusion machines, like ITER and DEMO, will need a reliable method for controlling or suppressing large ELMs.